[go: up one dir, main page]

WO2018029462A1 - Polymères ramifiés - Google Patents

Polymères ramifiés Download PDF

Info

Publication number
WO2018029462A1
WO2018029462A1 PCT/GB2017/052334 GB2017052334W WO2018029462A1 WO 2018029462 A1 WO2018029462 A1 WO 2018029462A1 GB 2017052334 W GB2017052334 W GB 2017052334W WO 2018029462 A1 WO2018029462 A1 WO 2018029462A1
Authority
WO
WIPO (PCT)
Prior art keywords
oil
polymer
chain ends
branched amphiphilic
amphiphilic polymer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/GB2017/052334
Other languages
English (en)
Inventor
Stephanie EDWARDS
Steve RANNARD
Andrew Owen
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Liverpool
Original Assignee
University of Liverpool
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Liverpool filed Critical University of Liverpool
Priority to US16/324,285 priority Critical patent/US20190218323A1/en
Priority to EP17761109.2A priority patent/EP3497142A1/fr
Publication of WO2018029462A1 publication Critical patent/WO2018029462A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/30—Macromolecular organic or inorganic compounds, e.g. inorganic polyphosphates
    • A61K47/32—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. carbomers, poly(meth)acrylates, or polyvinyl pyrrolidone
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/10—Dispersions; Emulsions
    • A61K9/107—Emulsions ; Emulsion preconcentrates; Micelles
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K9/00—Medicinal preparations characterised by special physical form
    • A61K9/10—Dispersions; Emulsions
    • A61K9/107—Emulsions ; Emulsion preconcentrates; Micelles
    • A61K9/1075—Microemulsions or submicron emulsions; Preconcentrates or solids thereof; Micelles, e.g. made of phospholipids or block copolymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/38—Polymerisation using regulators, e.g. chain terminating agents, e.g. telomerisation
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10—Esters
    • C08F220/26—Esters containing oxygen in addition to the carboxy oxygen
    • C08F220/28—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety
    • C08F220/285—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety and containing a polyether chain in the alcohol moiety
    • C08F220/286—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety and containing a polyether chain in the alcohol moiety and containing polyethylene oxide in the alcohol moiety, e.g. methoxy polyethylene glycol (meth)acrylate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F222/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical and containing at least one other carboxyl radical in the molecule; Salts, anhydrides, esters, amides, imides, or nitriles thereof
    • C08F222/10—Esters
    • C08F222/1006—Esters of polyhydric alcohols or polyhydric phenols
    • C08F222/102—Esters of polyhydric alcohols or polyhydric phenols of dialcohols, e.g. ethylene glycol di(meth)acrylate or 1,4-butanediol dimethacrylate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2438/00—Living radical polymerisation
    • C08F2438/01—Atom Transfer Radical Polymerization [ATRP] or reverse ATRP
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2438/00—Living radical polymerisation
    • C08F2438/03—Use of a di- or tri-thiocarbonylthio compound, e.g. di- or tri-thioester, di- or tri-thiocarbamate, or a xanthate as chain transfer agent, e.g . Reversible Addition Fragmentation chain Transfer [RAFT] or Macromolecular Design via Interchange of Xanthates [MADIX]

Definitions

  • the present invention relates to particular novel branched amphiphilic polymers, compositions containing them, and their methods of use.
  • the present invention relates to therapeutic methods for the treatment of diseases and to the use of such novel branched amphiphilic polymers in the manufacture of medicaments for use in the treatment and prevention of said diseases.
  • Branched polymers are polymer molecules of a finite size, which are branched. Branched polymers differ from cross-linked polymer networks which tend towards an infinite size having interconnected molecules and which are generally not soluble but often swellable. In some instances, branched polymers have advantageous properties when compared to analogous linear polymers. For instance, solutions of branched polymers are normally less viscous than solutions of analogous linear polymers. Moreover, higher molecular weight branched polymers can typically be solubilised more easily than corresponding linear polymers. In addition, branched polymers tend to have more end groups than a linear polymer and therefore generally exhibit strong surface-modification properties. Thus, branched polymers are useful components of many compositions utilised in a variety of fields.
  • Polymer systems that are capable of forming associations to biological materials and substrates, such as mucous or mucous membranes, offer potential for developing improved delivery methods for biologically active agents or other components.
  • such polymer systems may act by retaining a suitable dosage form at the site of action.
  • such polymer systems may also offer potential for improving systemic delivery and exposure of biologically active agent compounds by promoting diffusion and/or absorption of such compounds across biological surfaces. Retention of suitable dosage forms at such sites in order to achieve these benefits can be challenging and difficulties are often confounded when biologically active agents exhibit challenging physico-chemical properties, for example high lipophilicity and/or poor aqueous solubility.
  • Such agents often require non-conventional and complex drug delivery formulation techniques to provide suitably stable and effective dosage forms. Improvements in residence time at a specific location in the body can yield enhanced delivery and absorption benefits but may also allow the potential for localised and triggered release at these sites of action and/or absorption.
  • the particular branched amphiphilic polymers of the invention which can comprise large numbers of functional moieties capable of forming strong associations to biological substrates, are particularly suitable for preparing highly stable emulsions.
  • Such emulsions can contain biologically active agents and are accordingly useful in pharmaceutical and drug delivery applications.
  • particular emulsions stabilized by the branched amphiphilic polymers of the present invention are also able to selectively breakdown to release their contents upon contact and association with a biological substrate, such as mucous or a mucous membrane.
  • demulsifi cation and release is, inter alia, influenced by the size of the emulsion droplets, which can be varied and controlled to provide different release profiles, e.g. a particular release rate or dual release with immediate and sustained or delayed release components.
  • the present invention relates to a branched amphiphilic polymer, suitable for stabilizing an emulsion, comprising a plurality of polymer chains comprising hydrophobic chain ends, a plurality of polymer chains comprising functional chain ends capable of associating to a biological substrate and a plurality of branching units.
  • the functional chain ends are capable of forming a strong association to mucous or a mucous membrane.
  • the polymer chains can be made from vinyl monomers and the hydrophobic chain ends of the polymer chains can be alkyl chains of 5 carbon atoms or more. Conveniently, the functional chain ends of the polymer chains comprise one or more thiol groups.
  • the invention also relates to processes for the manufacture of said branched amphiphilic polymers and to compositions containing them.
  • the invention relates to pharmaceutical compositions (such as emulsion compositions) comprising the branched amphiphilic polymer, an effective amount of a biologically active agent or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier, diluent or excipient.
  • the composition is a highly stable oil-in water emulsion formulation that is capable of breaking down to release its contents upon contact and association with a biological substrate, such as mucous or a mucous membrane.
  • Figure 1 shows a schematic representation of a particular branched amphiphilic polymer of the invention, comprising primary linear polymer chains formed from hydrophilic vinyl monomers of poly(ethylene glycol) methyl ether methacrylate, which are branched by the use of ethylene glycol dimethacrylate branching units. Some of the chains have thiol functional chain ends (initiator: Go-BiB) and others have hydrophobic chain ends (initiator: dodecyl bromo isobutyrate, DBiB).
  • Figure 2 illustrates some common ways in which conventional oil-in-water emulsions can breakdown.
  • Figure 3 is a schematic representation of how a particular branched amphiphilic polymer of the invention may act to stabilize an emulsion at the oil/water interface.
  • Figure 4 shows the particle size distributions of emulsions stabilized by a particular branched amphiphilic polymer of the invention (DBiBo 25/SHGo(o.75)(pOEGMA 5 o-co-EGDMAo.8, i.e. thiol content is 75% of chain ends based on molar percent of initiator used during synthesis) after 5 days and 2 weeks post-preparation.
  • a particular branched amphiphilic polymer of the invention DBiBo 25/SHGo(o.75)(pOEGMA 5 o-co-EGDMAo.8, i.e. thiol content is 75% of chain ends based on molar percent of initiator used during synthesis
  • Figure 5 shows that emulsions stabilized by a particular branched amphiphilic polymer of the invention (DBiB 0 .25/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8) are stable (as assessed by optical microscopy) when encapsulated with a hydrophobic drug mimic (both Oil red O and Oil blue O).
  • DBiB 0 .25/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8) are stable (as assessed by optical microscopy) when encapsulated with a hydrophobic drug mimic (both Oil red O and Oil blue O).
  • Figure 6 shows that glass slides pre-coated with a layer of mucous when dipped into a concentrated emulsion containing Oil red O stabilized by a particular branched amphiphilic polymer of the invention (DBiB ( o.25)/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8) exhibit mucoadhesion and triggering of emulsion breakdown over time ( Figure 6 image on left taken immediately after application of the emulsion and image on right taken after 10 minutes). In contrast, when branched polymers only containing hydrophobic chain ends and no functional chain ends (i.e. DBiB) were assessed, no mucoadhesion was observed.
  • DBiB branched amphiphilic polymer of the invention
  • Figure 7 shows that two separately prepared emulsions with the same thiol content but different coloured dyed oil phases exhibit mucoadhesion and triggered release resulting in mixing of the two coloured dyes.
  • Figure 7, from left to right shows images taken at 0 mins, 2 mins and 5 mins.
  • Figure 8 shows that emulsions exhibit mucoadhesion and triggered release as a result of the emulsion droplets rupturing (optical microscopy images of mucous at 5x, lOx magnification). Figure 8, from left to right images taken at 0 mins and 5 mins.
  • Figure 9 shows that emulsions exhibit mucoadhesion and triggered release as a result of the emulsion droplets rupturing.
  • Optical images were taken at different magnifications to those shown in Figure 8 in order to provide a broad visual assessment of the emulsion droplets rupturing (optical microscopy images mucous at lOx, 20x magnification)
  • Figure 9 from left to right shows images taken at 5 mins and 10 mins.
  • Figure 10 shows the Z-average diameter (d.nm) of nanoemulsion samples at various ratios of solven oil in the dispersed phase stabilized with a thiol containing branched amphiphilic polymer of the invention (DBiB 0 .25/SHG 0 (o.75)(pOEGMA5o-co-EGDMAo.8).
  • Figure 1 1 shows the particle size distributions (Z-average and polydispersity) of nanoemulsions stabilized by a particular branched amphiphilic polymer of the invention (DBiBo.25/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8).
  • the data shows that the presence of the thiol group in the branched amphiphilic polymer did not adversely affect the stability of the nanoemulsion sample.
  • Figure 12 compares samples of nanoemulsions stabilized with branched polymers containing hydrophobic chain ends (DBiB 100%) against nanoemulsions stabilized with branched amphiphilic polymers of the current invention (DBiB (0.25)/SHGo (0.75), i.e. thiol content is 75% of chain ends based on molar percent of initiator added, composition also contained Oil red O at 0.1 wt% w.r.t. to castor oil). Samples containing only hydrophobic chain ends (i.e. unfunctionalised) do not show any adhesion and the emulsion was easily moved to the sides of the vial on light agitation. In contrast, nanoemulsions containing the functionalised moieties (thiol groups) are highly mucoadhesive.
  • Figures 13a and b show 1H MR spectra for XaniGo(o.75)/DBiB(o.25)(pOEGMA 5 o-co-EGDMAo.8) and SHG O (o.75)/DBiB(o.25)(pOEGMA 5 o-c0-EGDMAo.8).
  • Figure 14 shows the infrared spectra of a first generation dendron used to show the functional group stretches associated with the thiol group.
  • Figures 15a and b show the IR spectra for SHGo(o.75) DBiB ( o.25)(pOEGMA5o-co-EGDMAo.8) mixed with excess L-Cysteine and L-Cysteine alone.
  • Figures 16 and 17 show particle size distributions for blank emulsions, emulsions loaded with
  • Figure 20 shows an Amphotericin B fungus kill study including the efficacy of Amphotericin C - loaded emulsions.
  • Figures 21 and 22 show the results of cytotoxicity experiments using nanoemulsions prepared as described herein.
  • Figure 23 shows phalloidin staining images of cells treated with Cyclosporin A - loaded emulsions.
  • association to a biological substrate refers to association to a material, which is biological in nature, wherein the polymer or composition containing the polymer is held together with the biological material for an extended period of time by interfacial forces. It is to be understood that the term “association” refers to an interaction between the branched amphiphilic polymer of the invention or a composition containing it with the surface of a biological material.
  • the association includes for example adsorption, adhesion, covalent bonding, hydrogen bonding, ionic bonding, electrostatic attraction, Van-der-Waals interaction and polar interactions.
  • the biological substrate can be any biomaterial such as for example mucous, a mucous membrane, the extracellular matrix of a biological cell, bacterial biofilms, mucin layers and keratin (such as present in hair and skin).
  • the association is to mucous or a mucous membrane, the phenomenon typically referred to as mucoadhesion.
  • Branched amphiphilic polymers provided by the present invention include those described generally above, and are further illustrated by all classes, subclasses and species of each of these compounds disclosed herein. Conveniently, the branched amphiphilic polymer is non-gelled, non-crosslinked and processable.
  • polymer structures which are insoluble or crosslinked and/or exhibit high viscosity such as extensively crosslinked insoluble polymer networks, high molecular weight linear polymers, or microgels.
  • the branched amphiphilic polymer may for example be an addition polymer.
  • the branched amphiphilic polymer may for example be a polymer made from unsaturated, e.g. vinyl or allyl, monomers, such as for example acrylate or methacrylate monomers.
  • Branched vinyl polymers may be prepared by known methods, from monofunctional vinyl monomers and difunctional vinyl monomers (branching agents). They can be made by, but are not limited to being made by, living polymerisation, controlled polymerisation, step-growth polymerisation or conventional chain-growth polymerisation techniques such as free radical polymerisation. Several types of living and controlled polymerization are known in the art and suitable for use in the present invention. A preferred type of controlled free radical polymerisation is Atom Transfer Radical Polymerisation (ATRP); however other techniques such as Reversible Addition-Fragmentation chain-Transfer (RAFT) and Nitroxide Mediated Polymerisation (NMP) or conventional free-radical polymerisation controlled by the deliberate addition of chain-transfer agents are also suitable syntheses.
  • ATRP Atom Transfer Radical Polymerisation
  • RAFT Reversible Addition-Fragmentation chain-Transfer
  • NMP Nitroxide Mediated Polymerisation
  • each vinyl polymer chain starts at an initiator.
  • Copolymerization with difunctional vinyl monomers leads to branching between the chains.
  • brancher i.e. the difunctional vinyl monomer
  • this can be achieved by using a molar ratio of brancher to initiator of less than one: this assumes that the monomer (i.e. the monofunctional vinyl monomer) and the brancher (i.e. the difunctional vinyl monomer) have the same reactivity, that there is no or very limited intramolecular reaction, that the two functionalities of the brancher have the same or similar reactivity, and that reactivity remains the same or substantially unaffected even after part-reaction.
  • initiators and other reagents can be used in the polymerisation process.
  • Mixed initiators can be used to provide different chain end compositions.
  • convenient and effective initiators to introduce hydrophobic chain ends include alkyl halides (e.g. alkyl bromides).
  • effective initiators include azo compounds.
  • Initiators used to incorporate functional chain ends, such as thiol groups include but are not limited to xanthate and poly-xanthate initiators, such as for example Xani-Go-BiB, Xan 2 - Gi-BiB, Xan 4 -G 2 -BiB and Xan 8 -G 3 -BiB:
  • branched polymers include branched polyesters. These may be prepared by for example ring opening polymerization of monofunctional lactone monomers and difunctional lactone monomers (branching agents). Ring opening polymerization methods and materials are known in the art, for example from Nguyen et al, Polym Chem 2014, 5, 2997- 3008.
  • One sub-set of suitable branched polymers include those comprising ether or poly ether moieties, e.g. those comprising polyethylene glycol (PEG) or polyethylene oxide (PEO), e.g. those made from vinyl monomers comprising ether groups. We have found these to be convenient to prepare and to exhibit good properties, for example when used as emulsifiers in oil-in-water emulsions.
  • Suitable monomers for use in a method of preparing branched polymers having PEG groups include PEG-acrylate or other vinyl versions of PEG.
  • PEG-acrylate or other vinyl versions of PEG is oligo(ethylene glycol) methacrylate (OEGMA), also known as PEG-methacrylate.
  • This monomer allows the incorporation of multiple ether moieties.
  • This monomer already contains a number of ethylene oxide moieties.
  • polymerisation and branching is carried out simultaneously by mixing mono-functional and bifunctional monomers in a single feed.
  • the introduction of branches can be achieved after polymerisation of the primary vinyl chains.
  • this monomer can be polymerised via its vinyl moiety such that, before connection of the primary vinyl polymer chains via branches, it may contain for example 5 to 500 OEGMA units.
  • the degree of polymerisation (DP n ) of the primary chains of the branched amphiphilic polymer of the invention is between 50 and 100 monomer units.
  • Suitable monofunctional monomers include, but are not limited to, for example N-butyl methacrylate, N-butyl acrylate, N-butyl methacrylamide 2-hydroxypropyl methacrylate, 2- hydroxypropyl acrylate, ⁇ , ⁇ -diethyl amino ethyl methacrylate, ⁇ , ⁇ -diethyl amino ethyl acrylate, glycerol methacrylate, glycerol acrylate and 2-methacryloyloxyethyl phosphorylcholine.
  • Suitable types of difunctional monomer i.e. brancher
  • One example of a suitable brancher is ethylene glycol dimethacrylate (EGDMA). This is convenient and effective.
  • branchers include, but are not limited to, oligoethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, bisphenol A dimethacrylate,
  • polydimethylsiloxane dimethacrylate divinyl benzene, oligoethylene glycol diacrylate, polyethylene glycol diacrylate, bisphenol A diacrylate and polydimethylsiloxane diacrylate.
  • the branched amphiphilic polymer of the present invention can be understood to comprise a number of primary polymer chains held together with branches between the chains (preferably one branch or fewer per chain).
  • some of the chains ends are hydrophobic alkyl moieties.
  • Such hydrophobic alkyl chain ends may be incorporated into the branched polymer via a suitable initiator or chain transfer agent, e.g. via bromide initiators (such as bromo isobutyrates) or mercaptan chain transfer agents.
  • An initiator (or chain transfer agent) may include an alkyl chain of 5 carbon atoms or more.
  • the initiator is selected from dodecyl bromo isobutyrate (DBiB), hexyl bromo isobutyrate (HBiB) and ethyl bromo isobutyrate (EBiB).
  • DBiB dodecyl bromo isobutyrate
  • HBiB hexyl bromo isobutyrate
  • EBiB ethyl bromo isobutyrate
  • this is a convenient and effective way of imparting the required hydrophobic character so as to stabilise or "anchor into” the oil droplets. Furthermore, it is flexible: it enables the alkyl chain ends of the resultant polymer to be varied easily, simply by varying the initiator, and thereby provides an important means of tailoring the composition. In a particular embodiment, these hydrophobic "anchors" do not need to be present on each polymer chain.
  • the branched amphiphilic polymers of the current invention also comprise functional moieties.
  • the branched amphiphilic polymers comprise a plurality of polymer chains comprising functional chain ends capable of associating to a biological substrate.
  • an initiator may include a functional moiety capable of associating to a biological substrate.
  • the initiator employed to provide the functional moiety is selected from Xani-Go-BiB, Xan 2 -Gi-BiB, Xan 4 - G 2 -BiB and Xan 8 -G3-BiB.
  • the initiator employed to provide the functional moiety is selected from Xani-Go-BiB, Xan 2 -Gi-BiB, Xan 4 - G 2 -BiB and Xan 8 -G3-BiB.
  • the initiator employed to provide the functional moiety is selected from Xani-Go-BiB, Xan 2 -Gi-BiB, Xan 4 - G 2 -BiB and Xan 8 -G3-BiB.
  • mucoadhesive functionalities include charged polymers, such as poly(acrylic acid).
  • Polymers that have an overall negative net charge at pH values exceeeding the pKa of the polymer, with for example the presence of carboxyl and sulphate functional agroups can be suitable (Andrew, G. et al, 2008, Eu. Jr. Phrm. Biophrm., 71, 505-518).
  • mucoadhesive functionalities include polyacrylates (Khutoryanskiy, V., 2010, Macromolecular Bioscience, 11(6), 748-7) or polyethylene glycol modified poly(lactic-co-glycolic)acid polymers (Cu, Y., Saltzman, W.M, 2008, molecular pharmaceutics, 6(1),173-181).
  • branched amphiphilic polymers that comprise both hydrophobic alkyl chains and a functional moiety capable of associating to a biological substrate provide a convenient and effective way of imparting the required hydrophobic character so as to stabilise or "anchor" the oil droplets but also provide the ability to target and associate with a biological substrate.
  • Such polymers can be synthesised with two initiators at different ratios to give the two different required chain end compositions.
  • the branched amphiphilic polymers of the present invention are capable of associating with a biological substrate. Such functionality is achieved by polymer chain ends comprising a functional moiety capable of associating to a biological substrate.
  • Such association provides the potential to optimize localized drug delivery of biological agents, by retaining a suitable dosage form at the site of action (e.g. within any of the sites within the gastro-intestinal tract, including the mouth, stomach, intestine and colon), the bladder, the surface of the eye, the respiratory system (including the nasal cavity and the mucosal surfaces of the lungs), the skin, hair or parts of the reproductive organs (such as the vagina) or improving systemic delivery by promoting absorption across various biological surfaces. Retention of suitable dosage forms at such sites can be challenging, for example in the eye, where many drugs are quickly eliminated via the lacrimal gland (Urtti, A., 2006, Adv. Drug. Deliv. Rev.
  • the suitable dosage form in this embodiment is an emulsion formulation.
  • the branched amphiphilic polymers could also be used as therapeutic agents in their own right, for example to coat and protect damaged tissues (gastric ulcers or lesions of the oral mucosa) or to act as lubricating agents (in the oral cavity, eye and vagina).
  • the biological substrate to which the functional moiety capable of associating is mucous or a mucous membrane.
  • Mucous membranes are the moist surfaces lining the walls of various body cavities such as the gastrointestinal and respiratory tracts. They consist of a connective tissue layer (the lamina basement) above which is an epithelial layer, the surface of which is made moist usually by the presence of a mucous layer.
  • the epithelia may be either single layered (e.g. the stomach, small and large intestine and bronchi) or multilayered/stratified (e.g. in the oesophagus, vagina and cornea).
  • the former contain goblet cells which secrete mucous directly onto the epithelial surfaces, the latter contain, or are adjacent to tissues containing, specialized glands such as salivary glands that secrete mucous onto the epithelial surface.
  • Mucous is present as either a gel layer adherent to the mucosal surface or as a luminal soluble or suspended form. As mentioned above, mucous can present a barrier for local and systemic drug delivery.
  • the functional moiety capable of associating to a biological substrate comprises thiol groups.
  • the inventors have found that by incorporating such groups into at least one or more ends of the polymer chains of the branched amphiphilic polymer, the branched amphiphilic polymer is particularly useful in providing a means to target and associate with a biological substrate, such as for example mucous or a mucous membrane.
  • the thiol groups are incorporated into the polymer chains as xanthate functional groups.
  • Figure 1 provides details of a suitable branched polymer of the invention comprising the hydrophilic monomer poly(ethylene glycol) methyl ether methacrylate used to prepare the polymer chains, Go-BiB initiators used to provide functional chain ends comprising a xanthate functional group, DBiB used as initiator to provide hydrophobic chain ends and ethylene glycol dimethacrylate as branching unit.
  • branched amphiphilic polymers of the invention when branched amphiphilic polymers of the invention are deprotected to remove the xanthate and generate thiol functional groups and are employed as emulsifiers for oil-in-water emulsions encapsulating hydrophobic materials, the emulsion droplets associate with a biological substrate, such as for example mucous or a mucous membrane. Furthermore, droplets can rupture with time to provide a triggered release of their contents (e.g. biologically active agent). This targeted release provides a number of potential benefits for localized and systemic drug delivery applications.
  • the polymer's chains comprise a functional moiety capable of associating to a biological substrate.
  • 10-90% of the polymer chain ends carry the functional moiety.
  • at least 50%, 60% or 70% of the polymer chain ends carry functional chain ends.
  • 70-80%) (conveniently 75%) of the polymer chain ends carry functional chain ends.
  • the functional moieties are thiol groups.
  • a pharmaceutical composition comprising a branched amphiphilic polymer, an effective amount of a biologically active agent or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier, diluent, or excipient.
  • a pharmaceutical composition comprising an effective amount of a branched amphiphilic polymer, a biologically active agent or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier, diluent, or excipient for use as a medicament.
  • the phrase "effective amount” means an amount of a biologically active agent or composition containing a biologically active agent which is sufficient enough to significantly and positively modify the symptoms and/or conditions to be treated (e.g. provide a positive clinical response).
  • the effective amount of the biologically active agent for use in a pharmaceutical composition will vary with the intended therapeutic or prophylactic purpose, the particular condition being addressed, the severity of the condition, the duration of the treatment, the nature of concurrent therapy, the particular biologically active agent(s) being employed, the particular pharmaceutically-acceptable excipient(s)/carrier(s) utilized, and like factors within the knowledge and expertise of the attending physician.
  • the term "pharmaceutically acceptable” refers to those compounds (for example biologically active agent compounds described herein), materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
  • references to "treat”, “treating” or “treatment” include prophylaxis as well as the alleviation of established symptoms of a condition.
  • “Treating” or “treatment” of a state, disorder or condition therefore includes: (1) preventing or delaying the appearance of clinical symptoms of the state, disorder or condition developing in a human that may be afflicted with or predisposed to the state, disorder or condition but does not yet experience or display clinical or subclinical symptoms of the state, disorder or condition, (2) inhibiting the state, disorder or condition, i.e., arresting, reducing or delaying the development of the disease or a relapse thereof (in case of maintenance treatment) or at least one clinical or subclinical symptom thereof, or (3) relieving or attenuating the disease, i.e., causing regression of the state, disorder or condition or at least one of its clinical or subclinical symptoms.
  • compositions of the invention can be used for prophylaxis.
  • pharmaceutical compositions of the invention are used for prophylaxis to prevent the spread or transmission of infectious disease.
  • such compositions can be topical dosage forms for vaginal application.
  • the biologically active agent is a lipophilic drug with poor aqueous solubility.
  • suitable biologically active agents include for example the antiretroviral drugs Lopinavir (LPV) and Efavirenz (EFV), and the antibiotics Rifampicin and
  • compositions of the invention may be in a form suitable for oral use, for topical use (for example as creams, ointments, dermal and transdermal patches, gels, or aqueous or oily solutions or suspensions), for administration by inhalation (for example as a finely divided powder or a liquid aerosol), for administration by insufflation (for example as a finely divided powder), for parenteral administration (for example as a sterile aqueous or oily solution for intravenous, subcutaneous, or intramuscular dosing) or as a suppository for rectal dosing or pessary for vaginal administration.
  • compositions of the present invention are administered by oral administration.
  • the amount of biologically active ingredient that is combined with one or more excipients to produce a single dosage form will necessarily vary depending upon the host being treated with the therapeutic or prophylactic composition and the particular route of administration.
  • the size of the dose required for the therapeutic or prophylactic treatment of a particular disease state will also necessarily be varied depending on the host, the route of administration and the severity of the illness. The optimum dosage may be determined by the practitioner who is treating any particular patient.
  • the branched amphiphilic polymer is employed in an emulsion composition and the emulsions are of particular use in the pharmaceutical and drug delivery areas.
  • Emulsions are typically highly unstable mixtures of two immiscible phases, which wish to be separate. A high input of energy is often required in order to prevent separation, which can occur via various different mechanisms.
  • Figure 3 illustrates some common ways in which emulsions can breakdown.
  • Classical emulsions include mixtures of oil (dispersed phase) and water (continuous phase) and polymeric surfactants can be used to stabilise the two phases. Such polymeric surfactants can reside at the interface between oil and water to give a monodispersed oil phase.
  • Classical emulsions also include emulsions where a hydrophilic phase is dispersed in a hydrophobic phase (water-in-oil) or double emulsions, so called water-in-oil-in-water or the converse oil-in-water-in-oil emulsions.
  • water-in-oil water-in-oil
  • water-in-oil-in-water water-in-oil-in-water
  • converse oil-in-water-in-oil emulsions oil-in-water-in-oil emulsions.
  • the branched amphiphilic polymer of the current invention can comprise a low percentage of hydrophobic chain ends and still provide a storage stable dispersed phase even though the remaining chain ends comprise a large number of functional moieties capable of associating to a biological substrate.
  • Figure 3 is a schematic representation of how a particular branched amphiphilic polymer of the invention may act to stabilize an emulsion at the oil/water interface, where the low percentage of hydrophobic chain ends act as anchors into the oil droplet and serve to stabilize the emulsion.
  • the present invention provides an oil-in-water emulsion as described above, for use as a medicament.
  • the present invention also provides a corresponding method of medical treatment comprising administration of an effective amount of an oil-in-water emulsion as defined above, to a subject in need thereof.
  • the compositions are particularly effective in oral drug delivery.
  • the inventors have found that the emulsions are surprisingly effective in not only maintaining excellent stability but also in associating to a biological substrate and therefore optimising delivery and treatment.
  • a further aspect the present invention provides a method of preparing an oil-in-water emulsion comprising mixing an oil phase with an aqueous phase in the presence of a branched amphiphilic polymer, wherein said branched amphiphilic polymer is a non-gelled branched polymer comprising a plurality of polymer chains comprising hydrophobic chain ends, a plurality of polymer chains comprising functional chain ends capable of associating to a biological substrate and a plurality of branching units.
  • the biologically active agent and/or other component may be dissolved in an oil.
  • an oil For pharmaceutical uses and therapeutic administration the oil must of course be selected from oils that are suitable for, and safe for, those applications.
  • oils that fulfil this criterion.
  • the oil will be a good solvent for the material to be carried.
  • suitable oils include castor oil, coconut oil, dodecanoic acid, squalene, peanut oil, sesame oil and soy bean oil.
  • Castor oil is particularly preferred with some biologically active agents. Saturating the oil with the drug will give the maximum possible concentration of the biologically active agent in the final emulsion. The emulsion can easily be diluted if required.
  • Formulations containing various hydrophobic materials are carried, for example Curcumin, Flourescein and Nile Red can also be prepared.
  • a further solvent may be used during the preparation procedure in addition to the oil.
  • the solvent is typically miscible with the oil and would not adversely affect the solubility of the biologically active agent in the mixture.
  • the further solvent would not be present in the final emulsion and is therefore one which can be removed by evaporation or other methods.
  • Suitable volatile solvents include for example ethyl acetate, hexane, acetone or THF.
  • Ethyl acetate is one preferred solvent as it is not miscible with water, it is miscible with many oils, has appreciable water-solubility, evaporates easily and quickly, and has low toxicity.
  • the oil in which the biologically active agent or other hydrophobic material is dissolved
  • the ratio of oil to solvent can be selected to tailor the size of the emulsion droplets. Typically, the higher the solvent to oil ratio, the smaller the droplets in the final emulsion.
  • the amount, by volume, of solvent with respect to oil may for example be 50:50 or greater, e.g. 60:40 or greater, e.g. 70:30 or greater, e.g. 80:20 or greater, e.g. 90: 10 or greater, e.g. 95:5 or greater, e.g. 99: 1 or greater, e.g. 95:5 to 99.9:0.1, e.g. approximately 99: 1.
  • the emulsion is conveniently formed by mixing the oil phase (which optionally includes the volatile solvent) with an aqueous solution of the branched amphiphilic polymer.
  • the amount of aqueous phase relative to oil phase, and the concentration of the branched amphiphilic polymer within the aqueous phase, can be chosen to tailor the nature and properties of the emulsion.
  • Sufficient polymer should be used to stabilise the emulsion droplets.
  • the concentration of polymer can affect the size of the droplets. Without wishing to be bound by theory, it is believed that lower amounts of polymer lead to larger droplets due to there not being enough polymer to fully encapsulate the droplets and therefore leading to aggregation. Conversely, there is typically an upper limit of polymer required, such that above that amount no further stabilisation benefit will be observed and leading to free polymer in solution.
  • the preferred concentration of polymer in the aqueous phase is selected from approximately 0.1-99.9%, 0.5-99%, 1-90%, 1-50%, 1-20%, 2-10%, 3-7%, or approximately 5%.
  • the amount of oil (plus optional solvent) phase relative to the amount of aqueous phase (v/v) is approximately 90: 10 to 10:90, or 75:25 to 25:75, or 60:40 to 40:60, or approximately 50:50.
  • the oil phase and aqueous phase may be mixed and homogenised using any suitable method or apparatus to result in an oil-in-water emulsion.
  • the emulsion can comprise nanosized droplets and these can be determined by appropriate light scattering or laser diffraction methods.
  • the volatile solvent may be removed by any suitable method, for example by allowing it to evaporate, and/or by dilution and stirring and/or by passing gas (e.g. inert gas e.g. nitrogen) through the material.
  • gas e.g. inert gas e.g. nitrogen
  • the material can be simply left in unsealed containers to allow evaporation (e.g. in a fume cupboard) over a period of 12-48 hours, typically about 24 hours.
  • the z-average diameter of the emulsion droplets is typically less than lOOOnm. In a different embodiment, the z-average diameter of the emulsion droplets, as determined by dynamic light scattering (DLS), is typically between 1-100 ⁇ . The z-average diameters may be measured by DLS at 25°C.
  • the oil-in-water emulsion may have particles or droplets of different sizes to those described above, i.e. not necessarily having a z-average diameter of no greater than about 1000 nm or between 1-100 ⁇ .
  • the oil-in-water emulsion has a mixture of particles or droplets with different sizes to provide a controlled and tailored release profile (e.g. a dual release system comprising both immediate release and sustained or delayed release components).
  • an oil-in-water emulsion comprising an emulsifier, which is a branched amphiphilic polymer as described herein.
  • an emulsifier which is a branched amphiphilic polymer as described herein.
  • a pharmaceutical composition may contain two or more separately prepared emulsions compositions, in which each emulsion composition contains a different biologically active agent and/or other hydrophobic component(s).
  • each emulsion composition contains a different biologically active agent and/or other hydrophobic component(s).
  • the different biologically active agent and/or other hydrophobic component(s) can be kept separate in stable emulsions until contact with a biological substrate such as mucous or a mucous membrane, at which point the emulsions stabilized by the branched amphiphilic polymers of the present invention can selectively breakdown and release their contents. This can be particularly advantageous where such biologically active agent(s) and/or other hydrophobic component(s) would otherwise be unstable if co-formulated together.
  • the emulsions of the invention may also be useful in other areas where benefit from the stability and/or functional association with biological substrates is advantageous.
  • the emulsions of the invention may also be useful in mouthwash compositions, agrochemicals, veterinary applications, cosmetics and other consumer goods products, such as cleansing creams, ointments, pastes, lotions and shampoos.
  • 1-dodecanol (9.32 g, 50 mmol, 1.0 eqiv), triethylamine (6.07 g, 60 mmol, 1.2 eqiv) were dissolved in dichloromethane (70 mL).
  • a-bromoisobutyl bromide 13.80 g, 60 mmol, 1.2 eqiv was added dropwise via a pressure equalising dropping funnel and stirred in an ice bath under nitrogen. After addition reaction vessel was left to warm to room temperature and left to stir for
  • N,N'-Dicyclohexylcarbodiimide (4.81 g, 23.32 mmol, 1.1 eqiv) was dissolved in anhydrous dichloromethane (10 mL) under nitrogen flow and transferred to main reaction vessel via syringe and the reaction was left to stir at ambient temperature for 16 hours.
  • the resulting crude mixture was filtered, diluted in dichlorm ethane (100 mL) and washed with distilled water (2 x 100 mL) and once with brine (100 mL). The organic layer was dried over MgS0 4 .
  • Ethylene glycol (301.35 g, 4855 mmol, 50 eqiv.), triethylamine (20.33 g, 201 mmol, 2 eqiv.) were dissolved in anhydrous tetrahydrafuran (100 mL) and the reaction was stirred in an ice bath.
  • A-bromoisobutyrl bromide (22.32 g, 97.1 mmol, 1 eqiv.) was added dropwise over 30 minutes and the reaction was left stirring under nitrogen atmosphere at ambient temp for 16 hours.
  • OEGMA (5.00 g, 16 mmol, 50 eq.)
  • EGDMA 0.051 g, 0.32 mmol, 0.8 eq.
  • 2,2'-bipyridyl (0.100 g, 0.64 mmol, 2 eq.)
  • DBiB 0.0268 g, 0.08 mmol, 0.25 eq.
  • Xan-G 0 -BiB 0.089 g, 0.24 mmol, 0.75 eq.
  • OEGMA (5.00 g, 16 mmol, 50 eq.)
  • 2,2'-bipyridyl (0.100 g, 0.64 mmol, 2 eq.)
  • DBiB 0.0268 g, 0.08 mmol, 0.25 eq.
  • Xani-G 0 - BiB 0.089 g, 0.24 mmol, 0.75 eq.
  • the vessel was sealed and degassed with dry nitrogen for 5 minutes, CuCl(I) (0.032 g, 0.32 mmol, 1 eq.) was added and the reaction vessel sealed.
  • RBF was immersed in silicon oil bath at 40°C and left to react until complete conversion, approx. 24 hrs.
  • Anisole was added as internal standard for 1 H MR conversion of monomer peaks.
  • Polymerisation terminated by exposure to air and dilution in THF. Copper catalyst removed by neutral alumina column, solvent removed in vacuo and crude polymer precipitated twice into cold hexane. Residual solvent removed in vacuo.
  • DBiB x /Xani-G 0 - BiBy(pOEGMA 5 o-co-EGDMAo.8) (0.599 g, 1.66 mmol, 1 eqiv.) was dissolved in tetrahydrafuran (10 mL) and degassed with dry nitrogen for ⁇ 5 minutes.
  • Butyl amine (0.38 mL, 4.15 mmol, 2.5 eqiv.) was added to the reaction vessel and left to stir for 1.5 hrs.
  • Solvent removed and crude product precipitated twice into cold hexane. Residual solvent removed in vacuo.
  • Aqueous polymer solutions were prepared at 5 mg/mL of branched amphilic polymer for the water phase of the emulsion.
  • Emulsions were prepared at a 1 : 1 v:v ratio of oil: water, where the oil phase was dodecane.
  • Emulsions were homogenised via over-head shear homogenisation (IKA T 25 ULTRA-TURRAX) for 2 minutes at 24,000 rpm. Emulsions are left over night before characterisation of droplet using light scattering was carried out (Malvern mastersizer 2000).
  • Figure 4 shows the particle size distributions of emulsions stabilized by a particular branched amphiphilic polymer of the invention (DBiBo 25/SHGo(o.75)( OEGMA 5 o-co-EGDMAo.8, i.e. thiol content is 75% of chain ends based on molar percent of initiator used during synthesis) after 5 days and 2 weeks post-preparation.
  • a particular branched amphiphilic polymer of the invention (DBiBo 25/SHGo(o.75)( OEGMA 5 o-co-EGDMAo.8, i.e. thiol content is 75% of chain ends based on molar percent of initiator used during synthesis) after 5 days and 2 weeks post-preparation.
  • the presence of a large number of thiol groups in the branched amphiphilic polymer did not adversely affect the stability of the sample (as assessed by laser diffraction using a Malvern Mastersizer).
  • Aqueous polymer solutions were prepared at 5 mg/mL of branched amphiphilic polymer for the water phase of the emulsion.
  • Emulsions were prepared at a 1 : 1 v:v ratio of oil: water, where the oil phase was dodecane.
  • Oil red O or Oil blue O (0.5 wt% w.r.t. dodecane) were used as a hydrophobic drug mimic.
  • Emulsions were homogenised via over-head shear homogenisation (IKA T 25 ULTRA-TURRAX) for 2 minutes at 24,000 rpm. Emulsions are left over night before characterisation of droplet using light scattering was carried out (Malvern mastersizer 2000).
  • Figure 5 shows that emulsions stabilized by a particular branched amphiphilic polymer of the invention (DBiBo.25/SHGo(o.75)(pOEGMA 5 o-co-EGDMAo.8) are stable (as assessed by optical microscopy) when encapsulated with a hydrophobic drug mimic (both Oil red O and Oil blue O).
  • DBiBo.25/SHGo(o.75)(pOEGMA 5 o-co-EGDMAo.8 are stable (as assessed by optical microscopy) when encapsulated with a hydrophobic drug mimic (both Oil red O and Oil blue O).
  • Biosimilar mucous was synthetically prepared to mimic that which is normally secreted in the gastro-intestinal tract.
  • the mucous was prepared with porcine mucin/lipids found in natural mucous, which contains cysteine. The procedure used is described in Boegh. M et al, 2014, European journal of Pharmaceutics and Biopharmaceutics, 87(2), 227-235.
  • the biosimilar mucous was coated onto glass slides or poured into glass vials and used for the emulsion assessments as described below.
  • Figure 6 shows that glass slides pre-coated with a layer of mucous when dipped into a concentrated emulsion containing Oil red O stabilized by a particular branched amphiphilic polymer of the invention (DBiB ( o.25)/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8) exhibit mucoadhesion and triggering of emulsion breakdown over time ( Figure 6 image on left taken immediately after application of the emulsion and image on right taken after 10 minutes). In contrast, when branched polymers only containing hydrophobic chain ends and no functional chain ends (i.e. DBiB) were assessed, no mucoadhesion was observed.
  • DBiB branched amphiphilic polymer of the invention
  • Figure 7 shows that two separately prepared emulsions with the same thiol content but different coloured dyed oil phases exhibit mucoadhesion and triggered release resulting in mixing of the two coloured dyes.
  • Emulsions used are oil-in-water emulsions at 1 : 1 ratio of oil: water where the dispersed phase is dodecane and the continuous phase is an aqueous polymer solution.
  • the branched amphiphilic polymer used is DBiB ( o.25)/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8) at 5 mg/mL w.r.t. to aqueous phase.
  • Oil red O or Oil blue O was incorporated at 0.5 wt.% w.r.t. to oil phase.
  • Emulsions were homogenized via over-head shear homogenisation (IKA T 25 ULTRA- TURRAX) for 2 minutes at 24,000 rpm. 100 ⁇ of each emulsion was applied to the surface of the biosimilar mucous.
  • Figure 7, from left to right shows images taken at 0 mins, 2 mins and 5 mins.
  • Figure 8 shows that emulsions exhibit mucoadhesion and triggered release as a result of the emulsion droplets rupturing (optical microscopy images of mucous at 5x, lOx magnification).
  • Emulsions used are oil-in-water emulsions at 1 : 1 ratio of oikwater where the dispersed phase is dodecane and continuous phase is aqueous polymer solution.
  • the branched amphiphilic polymer used is DBiB(o.25)/SHGo(o.75)(pOEGMA 5 o-co-EGDMAo.8) at 5 mg/mL w.r.t. to aqueous phase.
  • Oil red O or Oil blue O was incorporated at 0.5 wt% w.r.t. to oil phase.
  • Emulsions were homogenized via over-head shear homogenisation (IKA T 25 ULTRA- TURRAX) for 2 minutes at 24,000 rpm. 100 ⁇ of each emulsion was applied to the surface of the biosimilar mucous. Figure 8, from left to right images taken at 0 mins and 5 mins.
  • Figure 9 shows that emulsions exhibit mucoadhesion and triggered release as a result of the emulsion droplets rupturing.
  • Optical images were taken at different magnifications to those shown in Figure 8 in order to provide a broad visual assessment of the emulsion droplets rupturing (optical microscopy images mucous at lOx, 20x magnification)
  • Emulsions used are oil-in-water emulsions at 1 : 1 ratio of oil: water where the dispersed phase is dodecane and continuous phase is aqueous polymer solution.
  • the branched amphiphilic polymer used is DBiB(o.25)/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8) at 5 mg/mL w.r.t. to aqueous phase. Oil red O or Oil blue O was incorporated at 0.5 wt% w.r.t. to oil phase.
  • Figure 9 from left to right shows images taken at 5 and 10 mins.
  • Nanoemulsions were formulated using the solvent evaporation technique.
  • the oil phase is a mixture of two miscible oils, one a volatile solvent. As the volatile solvent evaporates, the nonvolatile section of the oil droplet shrinks to the nanoscale.
  • the oil phase is composed of ethyl acetate: castor oil in a ratio of 50:50, 60:40, 70:30, 80:20, 90: 10 or 99: 1.
  • the oil: water ratio was 1 : 1, with the water phase being aqueous polymer solution at 5 wt%.
  • Emulsions formulated via homogenisation using an over-head shear homogeniser (IKA T 25 ULTRA-TURRAX) for 2 minutes at 24,000 rpm. Emulsions are left overnight until all ethyl acetate is removed and analysis performed using dynamic light scattering (malver, zetasizer nano)
  • Figure 10 shows the Z-average diameter (d.nm) of nanoemulsion samples at various ratios of solven oil in the dispersed phase stabilized with a thiol containing branched amphiphilic polymer of the invention (DBiB 0 .25/SHG 0 (o.75)(pOEGMA5o-co-EGDMAo.8).
  • Figure 11 shows the particle size distributions (Z-average and polydispersity) of nanoemsulsions stabilized by a particular branched amphiphilic polymer of the invention (DBiB 0 .25/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8)-
  • the continuous phase is water and the dispersed phase is castor oil stabilized by the branched amphiphilic polymer.
  • the branched amphiphilic polymer was used as an aqueous polymer solution at 5 wt% and the dispersed phase was ethyl acetate/castor oil (99: 1 ratio).
  • the ethyl acetate was removed during the process resulting in a size reduction of the emulsion droplets into the nano-range.
  • the data shows that the presence of the thiol group in the branched amphiphilic polymer did not adversely affect the stability of the nanoemulsion sample.
  • Figure 12 compares samples of nanoemulsions stabilized with branched polymers containing hydrophobic chain ends (DBiB 100%) against nanoemulsions stabilized with branched amphiphilic polymers of the current invention (DBiB (0.25)/SHGo (0.75), i.e. thiol content is 75%) of chain ends based on molar percent of initiator added, composition also contained Oil red O at 0.1 wt%> w.r.t. to castor oil). Samples containing only hydrophobic chain ends (i.e. unfunctionalised) do not show any adhesion and the emulsion was easily moved to the sides of the vial on light agitation.
  • nanoemulsions containing the functionalised moieties (thiol groups) were highly mucoadhesive.
  • the methodology employed was a simple visual mucoadhesion experiment, in which two sample vials containing biosimilar mucous (1 mL) were set up. To each vial emulsions containing polymeric surfactants DBiB(pOEGMA 50 -co-EGDMA- o.s) or DBiB 0 .25/SHGo(o.75)(pOEGMA5o-co-EGDMAo.8) (100 ⁇ ) were added respectively. Over 5 minutes the samples were monitored to witness any adhesion to the surface of the synthetic mucous.
  • IR Infrared Spectrometry
  • Macroemulsions were prepared as described above, except that the oil phase was changed from dodecane to squalene due to this being more biologically favourable.
  • Macroemulsions with encapsulated drugs for ocular drug delivery are Macroemulsions with encapsulated drugs for ocular drug delivery
  • Aqueous polymer solutions were prepared at 5 mg/mL of branched amphiphilic polymer for the water phase of the emulsion.
  • Emulsions were prepared at a 1 : 1 v:v ratio of oil: water, where the oil phase was squalene.
  • Amphotericin B and Cyclosporin A were loaded in the oil phase at the clinical topical dose concentration, 0.15% w/v and 0.05% w/v respectively.
  • Emulsions were homogenised via over-head shear homogenisation (IKA T 25 ULTRA- TURRAX) for 2 minutes at 24,000 rpm. Emulsions were left over night before characterisation of droplet size using light scattering was carried out (Malvern mastersizer 2000).
  • Figure 16 shows the particle size distributions of the above-mentioned non- mucoadhesive macroemulsions (a blank emulsion, one loaded with Amphotericin B, and one loaded with Cyclosporin A).
  • Figure 17 shows the particle size distribution of the above-mentioned mucoadhesive macroemulsions (a blank emulsion, one loaded with Amphotericin B, and one loaded with Cyclosporin A).
  • Nanoemulsions were formulated using the solvent evaporation technique as described above. Amphotericin B and Cyclosporin A were loaded in the oil phase at the clinical topical dose concentration, 0.15% w/v and 0.05% w/v respectively.
  • Figure 18 shows the particle size distributions of the Amphotericin B loaded nanoemulsions
  • Figure 19 shows the particle size distributions of the Cyclosporin A loaded nanoemulsions (both non- and mucoadhesive), analysed by dynamic light scattering.
  • the following table shows a comparison of the hydrodynamic diameter and polydispersity (Pdl) of nanoemulsions loaded with Amphotericin B and Cyclosporin A against a blank emulsion.
  • Agar petri dishes were coated with Candida albicans and left to incubate at 35°C.
  • a drop of amphotericin B loaded nanoemulsion was placed onto the petri dish at three concentrations and assessed against two controls, blank emulsion and fungizone, a current manufactured amphotericin B product. The experiment was repeated in triplicate and incubated at 35°C.
  • Figure 20 shows an Amphotericin B fungus kill study with Candida albicans, assessing the kill level of the emulsions at varying concentrations. From top of petri dish then left to right; F) Fungizone negative control, 1) 194 mg/mL, 2) 282 mg/mL, 3) 4117 mg/mL and B) blank emulsion positive control.
  • HCE-t Human Corneal Epithelial cells-transformed
  • Controls include: Negative control - healthy cells treated solely with media, Positive control - cells treated with 100% DMSO to induce cell death from lhr onwards, and cells only to assure there is no background noise on the fluorescent plate reader.
  • Figure 21 shows overall cytotoxicity of mucoadhesive nanoemulsion determined from reszaurin assay. HCE-t cells exposed over a range of dilutions of emulsion in media.
  • Figure 22 shows overall cytotoxicity of non-mucoadhesive nanoemulsion determined from reszaurin assay. HCE-t cells exposed over a range of dilutions of emulsion in media.
  • Figure 23 shows Human Corneal Epithelium Cells transformed stained with phalloidin (green) and 4', 6-diamidino-2-phenylindole (DAPI). From top, left to right - A) Concentrated emulsion, B) 1 in 2 dilution, C) 1 in 4, D) 1 in 6, E) 1 in 8, F) 1 in 10, G) 1 in 1 1, H) 1 in 12, 1) 1 in 13, J) 1 in 14, K) 1 in 20, L) 1 in 30, M) media only. Images at 20x magnification, Nikon TI-E microscope. Human corneal epithelium cells (HCE-t) were seeded onto a 48 well plate at a density of 15,000 cells/well, and left to establish a monolayer for four days.
  • HCE-t Human corneal epithelium cells
  • Nanoemulsion loaded with Cyclosporin A at the topical dose (0.05% w/v) was applied to the cells in triplicate over a range of serial dilutions of emulsion in media (DMEM:F12, 10% FCS), and incubated at 37°C for 24 hours. After incubation, the emulsion was removed and the cells washed with phosphate buffered saline, PBS, (500 [iL) then fixed with neutral buffered formalin (NBF, 10% formalin, approx. 4% formaldehyde), for 10 minutes. NBF was removed and the cells washed again with PBS.
  • phosphate buffered saline, PBS (500 [iL) then fixed with neutral buffered formalin (NBF, 10% formalin, approx. 4% formaldehyde)
  • DAPI is a blue fluorescent DNA stain, which binds to the adenine- thymine rich areas, so is able to stain the nuclei of the cells.

Landscapes

  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Animal Behavior & Ethology (AREA)
  • Epidemiology (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Polymers & Plastics (AREA)
  • Dispersion Chemistry (AREA)
  • Biophysics (AREA)
  • Molecular Biology (AREA)
  • Inorganic Chemistry (AREA)
  • Medicinal Preparation (AREA)

Abstract

La présente invention concerne un polymère amphiphile ramifié, approprié pour stabiliser une émulsion, comprenant une pluralité de chaînes polymères comprenant des extrémités de chaînes hydrophobes ; une pluralité de chaînes polymères comprenant des extrémités de chaînes fonctionnelles pouvant s'associer à un substrat biologique ; et une pluralité de motifs de ramification. La présente invention concerne également des compositions pharmaceutiques contenant lesdits polymères amphiphiles ramifiés, leurs méthodes d'utilisation et leurs procédés de préparation.
PCT/GB2017/052334 2016-08-08 2017-08-08 Polymères ramifiés Ceased WO2018029462A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US16/324,285 US20190218323A1 (en) 2016-08-08 2017-08-08 Branched polymers
EP17761109.2A EP3497142A1 (fr) 2016-08-08 2017-08-08 Polymères ramifiés

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB1613584.0 2016-08-08
GB201613584 2016-08-08

Publications (1)

Publication Number Publication Date
WO2018029462A1 true WO2018029462A1 (fr) 2018-02-15

Family

ID=59746246

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2017/052334 Ceased WO2018029462A1 (fr) 2016-08-08 2017-08-08 Polymères ramifiés

Country Status (3)

Country Link
US (1) US20190218323A1 (fr)
EP (1) EP3497142A1 (fr)
WO (1) WO2018029462A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020203998A1 (fr) * 2019-03-29 2020-10-08 株式会社日本触媒 Composé amphiphile, et composition de résine à usage médical et additif de médicament utilisant chacun ledit composé amphiphile
JP2023038930A (ja) * 2021-09-07 2023-03-17 学校法人近畿大学 眼表面薬物滞留化剤およびこれを含む点眼剤、並びに、これらの剤を用いた眼表面薬物滞留方法および眼科疾患治療方法
CN116284617B (zh) * 2021-12-03 2025-11-07 四川大学华西医院 一种刺激响应性的线性-树枝状嵌段聚合物及其制药用途

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2128180A1 (fr) * 2008-05-29 2009-12-02 Unilever N.V. Polymères amphiphiles ramifiés et leur utilisation en tant qu'agents émulsifiants
WO2010125341A1 (fr) * 2009-04-28 2010-11-04 Unilever Plc Copolymère ramifié amphiphile, ses procédés de préparation, émulsions, emu et utilisations
WO2013177523A2 (fr) * 2012-05-25 2013-11-28 Johnson & Johnson Vision Care, Inc. Polymères et matériaux de nanogel et leurs procédés de fabrication et d'utilisation
US20150266986A1 (en) * 2014-03-20 2015-09-24 National University Of Ireland, Galway Multifunctional Hyperbranched Polymers

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050281775A1 (en) * 2004-06-16 2005-12-22 Carrington Stephen D Mucoadhesive and bioadhesive polymers

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2128180A1 (fr) * 2008-05-29 2009-12-02 Unilever N.V. Polymères amphiphiles ramifiés et leur utilisation en tant qu'agents émulsifiants
WO2010125341A1 (fr) * 2009-04-28 2010-11-04 Unilever Plc Copolymère ramifié amphiphile, ses procédés de préparation, émulsions, emu et utilisations
WO2013177523A2 (fr) * 2012-05-25 2013-11-28 Johnson & Johnson Vision Care, Inc. Polymères et matériaux de nanogel et leurs procédés de fabrication et d'utilisation
US20150266986A1 (en) * 2014-03-20 2015-09-24 National University Of Ireland, Galway Multifunctional Hyperbranched Polymers

Also Published As

Publication number Publication date
US20190218323A1 (en) 2019-07-18
EP3497142A1 (fr) 2019-06-19

Similar Documents

Publication Publication Date Title
Fenyves et al. Aqueous self-assembly of giant bottlebrush block copolymer surfactants as shape-tunable building blocks
US7204997B2 (en) Responsive microgel and methods related thereto
Nakagawa et al. Design of high-performance anti-adhesion agent using injectable gel with an anti-oxidative stress function
Buzza et al. Water-in-water emulsions based on incompatible polymers and stabilized by triblock copolymers–templated polymersomes
Bailly et al. Poly (N-vinylpyrrolidone)-block-poly (vinyl acetate) as a drug delivery vehicle for hydrophobic drugs
Hu et al. Smart pH-responsive polymeric micelles for programmed oral delivery of insulin
Sahle et al. Formulation and comparative in vitro evaluation of various dexamethasone-loaded pH-sensitive polymeric nanoparticles intended for dermal applications
Rezaei et al. Folate-decorated thermoresponsive micelles based on star-shaped amphiphilic block copolymers for efficient intracellular release of anticancer drugs
Jones et al. Reverse polymeric micelles for pharmaceutical applications
Yang et al. Fabrication and evaluation of the novel reduction-sensitive starch nanoparticles for controlled drug release
RU2523714C2 (ru) Полимерные системы доставки действующих веществ
Zeng et al. Tailoring the droplet size of Pickering emulsions by PISA synthesized polymeric nanoparticles
Sang et al. Preparation of pH/redox dual responsive polymeric micelles with enhanced stability and drug controlled release
JP7038054B2 (ja) 粘膜付着型薬物送達のためのミセル
Senthilkumar et al. Solubilization and interaction of ciprofloxacin with pluronics and their mixed micelles
Skandalis et al. PLMA‐b‐POEGMA amphiphilic block copolymers: Synthesis and self‐assembly in aqueous media
Liu et al. Aldehyde surface-functionalized shell cross-linked micelles with pH-tunable core swellability and their bioconjugation with lysozyme
US20190218323A1 (en) Branched polymers
CN108498483A (zh) 一种pH/还原响应性聚氨基酸两性离子纳米颗粒的制备方法
JP2000516614A (ja) 製薬適用用組成物
Laaser et al. Architecture-Dependent Stabilization of Polyelectrolyte Complexes between Polyanions and Cationic Triblock Terpolymer Micelles
Pillai et al. A multitechnique approach on adsorption, self-assembly and quercetin solubilization by Tetronics® micelles in aqueous solutions modulated by glycine
Diaz et al. Synthesis and micellization properties of triblock copolymers PDMAEMA-b-PCL-b-PDMAEMA and their applications in the fabrication of amphotericin B-loaded nanocontainers
CN101484482A (zh) 两步细乳液工艺
US10653783B2 (en) Sustained release of bioactive factors from zwitterionic hydrogels

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17761109

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2017761109

Country of ref document: EP

Effective date: 20190311